One-Pot Syntheses of 2-N-Alkylamino-, 2-N-Phenylamino-, 2-N, N-Dialkylamino-, and 2-N-Alkyl-N-phenylaminothiophenes

Abstract

A number of 2‐N‐alkylamino‐ or 2‐N‐phenylamino‐, 2‐N, N‐dialkylamino‐, and 2‐N‐alkyl‐N‐phenylaminothiophenes have been prepared in good yields by adding a solution of tert‐butylalcohol and potassium tert‐butoxide in dimethylsulfoxide to a solution of the adduct from a lithiated 1‐alkyne, RCH2C≡CLi, or the lithiated allene, tBuCH=C=CHLi, and isothiocyanate, R′N=C=S, in tetrahydrofuran and subsequently hydrolyzing the reaction mixture or quenching it with methyl iodide.

Three-Component Reaction between Isonicotinohydrazide, Potassium Selenocyanate and Aroyl Chlorides: Synthesis of 1,2,4-Triazole-3-Selones

“…The carbonyl stretching vibrations were observed as a strong absorption band at 1627 cm −1 . The C=Se group resonance in the 13 C NMR spectra of 4a appeared at 168.6 ppm.…”

“…The structures of compounds 4a-f were deduced from elemental analyses and their IR, 1 H NMR and 13 C NMR spectra. The mass spectra of compounds 4a-f are fairly similar and displayed appropriate molecular ion peaks.…”

“…IR spectra were recorded on a Shimadzu IR-470 spectrometer. NMR spectra were obtained on a Brucker DRX 500 Avance spectrometer ( 1 H NMR at 500 Hz, 13 C NMR at 125 Hz) in DMSO-d 6 using TMS as an internal standard. Chemical shifts (δ) are given in ppm.…”

Modular Synthesis of 5-Substituted Thiophen-2-yl C-2′-Deoxyribonucleosides

“…These reactions were successfully used for amination of halopyridine C -nucleosides. – Lithium bis(trimethylsilyl)amide (LiN(SiMe 3 ) 2 ) was used as an ammonia equivalent for introduction of the amino group, but reaction gave only products of degradation. It is not surprising since aminothiophenes are known to be very unstable in unprotected form . Therefore, we focused on the introduction of a dimethylamino group.…”

PPh2Me-Mediated Tandem Reaction of 2-Alkyl-2,3-butadienoates with Isothiocyanates: Formation of 2-Aminothiophenes

“…19,20 Furthermore, to extend the scope of electron-deficient olefins or allenes involving [3 + 2] cycloaddition reactions, in 2006, Virieux 21 reported a novel PPh 3 -catalyzed [3 + 2] cycloaddition reaction of phenyl isothiocyanate with electron-deficient allenes, which offered a new way to synthesize 2-aminothiophenes. 22,23 However, the isolated yields of products remained low in all tested conditions (Scheme 1). On the other hand, 2-alkyl-2,3-butadienoates have been employed in the phosphine-catalyzed [4 + 2] cycloaddition reactions with imines or arylmethylidenemalononitriles by Kwon.…”